We classify generators of quantum Markov semigroups on (h), with h finite-dimensional and with a faithful normal invariant state ρ satisfying the standard quantum detailed balance condition with an anti-unitary time reversal θ commuting with ρ, namely $tr\left({\rho }^{1/2}x{\rho }_t^{1/2}\left(y\right)\right)=tr({\rho }^{1/2}\theta y*\theta {\rho }_t^{1/2}(\theta x*\theta ))$ for all x,y ∈ and t ≥ 0. Our results also show that it is possible to find a standard form for the operators in the Lindblad representation of the generators extending the standard form of generators of quantum Markov semigroups satisfying the usual...